Hello friends, this is my first thread, sorry for ignorance, I researched a lot here in the forum and did not find the solution. I've had my n9 for 6 years, and every once in a while I flash him (flasher -f -F DFL61_HARMATTAN_40.2012.21-3_PR_LEGACY_001-OEM1-958_ARM.bin -F DFL61_HARMATTAN_40.2012.13-7.LTA_EMMC_LTA.bin --erase-user-data). But since the last flash last week, I can not install some applications. Apparently the error is 255 (setup interrupted)Operation failed: E: sub-process Usr/bin/dpkg returned an error code (255). I must have flashed some 50 times my n9 during this 6 years and always managed to install my apps. But this time around 30 percent of the apps I want to install is giving this error. Do you have any idea what's wrong?

I have the same error & this terminal error:
Aegis rejecting [filename]: package '[package name]' origin cannot be determined -- signature check failed
As I'm new to the phone, I haven't yet figured out how to do the solution steps (eg. how to refresh packages list).

Hello friends. I think I found the solution after searching here in the forum. Has to do with the validity of application certificates. Many that I usually install are outdated certificates. Using aegis hack(http://talk.maemo.org/showthread.php?t=90750) solve the problem. But it has a simpler way that also solves by simply changing the phone date to a few years ago. An example application that is impossible to install is the Reboot (https://openrepos.net/content/kamengatalica/reboot). Test with today's date(can not install without the aegis hack) and then try to put the year 2015 that will work(even without installing the aegis hack)

Hello friends. I think I found the solution after searching here in the forum. Has to do with the validity of application certificates. Many that I usually install are outdated certificates. Using aegis hack(http://talk.maemo.org/showthread.php?t=90750) solve the problem. But it has a simpler way that also solves by simply changing the phone date to a few years ago. An example application that is impossible to install is the Reboot (https://openrepos.net/content/kamengatalica/reboot). Test with today's date(can not install without the aegis hack) and then try to put the year 2015 that will work(even without installing the aegis hack)